A color laser printer known in the art has a plurality of developing stations for forming images corresponding to each of the colors. Each developing station has a photosensitive drum on the surface of which an electrostatic latent image is formed in accordance with laser light, and a transfer roller for visualizing the electrostatic latent image by toner and transferring the toner image to a printing paper transported to the transfer roller. Thus, images of a plurality of colors are transferred to the printing paper to print out a full-color image.
Such a printer that prints an image using a plurality of photosensitive drums has a decoder and a FIFO buffer associated with each photosensitive drum. High-speed printing of a full-color image can be achieved by supplying each of the image forming stations with video data of respective ones of the colors via the respective decoder and FIFO buffer concurrently and forming images corresponding to the colors concurrently using each of the photosensitive drums.
However, a printer of this type is such if the size of the printing paper is small or if has been decided in advance that the size of the printing paper used is smaller than a prescribed size, then it is conceivable that the printer may be put to practical use satisfactorily even if image formation for each of the colors is executed successively in conformity with transport of the print paper without forming images simultaneously on all of the photosensitive drums with which the printer is equipped.